?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Linux 3.8-rc7
[cris-mirror.git] / arch / x86 / kernel / ptrace.c
blobb629bbe0d9bdeee5a416a8a6390167e595cf6036
1 /* By Ross Biro 1/23/92 */
2 /*
3 * Pentium III FXSR, SSE support
4 * Gareth Hughes <gareth@valinux.com>, May 2000
5 */
6
7 #include <linux/kernel.h>
8 #include <linux/sched.h>
9 #include <linux/mm.h>
10 #include <linux/smp.h>
11 #include <linux/errno.h>
12 #include <linux/slab.h>
13 #include <linux/ptrace.h>
14 #include <linux/regset.h>
15 #include <linux/tracehook.h>
16 #include <linux/user.h>
17 #include <linux/elf.h>
18 #include <linux/security.h>
19 #include <linux/audit.h>
20 #include <linux/seccomp.h>
21 #include <linux/signal.h>
22 #include <linux/perf_event.h>
23 #include <linux/hw_breakpoint.h>
24 #include <linux/rcupdate.h>
25 #include <linux/module.h>
26 #include <linux/context_tracking.h>
27
28 #include <asm/uaccess.h>
29 #include <asm/pgtable.h>
30 #include <asm/processor.h>
31 #include <asm/i387.h>
32 #include <asm/fpu-internal.h>
33 #include <asm/debugreg.h>
34 #include <asm/ldt.h>
35 #include <asm/desc.h>
36 #include <asm/prctl.h>
37 #include <asm/proto.h>
38 #include <asm/hw_breakpoint.h>
39 #include <asm/traps.h>
40
41 #include "tls.h"
42
43 #define CREATE_TRACE_POINTS
44 #include <trace/events/syscalls.h>
45
46 enum x86_regset {
47 REGSET_GENERAL,
48 REGSET_FP,
49 REGSET_XFP,
50 REGSET_IOPERM64 = REGSET_XFP,
51 REGSET_XSTATE,
52 REGSET_TLS,
53 REGSET_IOPERM32,
54 };
55
56 struct pt_regs_offset {
57 const char *name;
58 int offset;
59 };
60
61 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
62 #define REG_OFFSET_END {.name = NULL, .offset = 0}
63
64 static const struct pt_regs_offset regoffset_table[] = {
65 #ifdef CONFIG_X86_64
66 REG_OFFSET_NAME(r15),
67 REG_OFFSET_NAME(r14),
68 REG_OFFSET_NAME(r13),
69 REG_OFFSET_NAME(r12),
70 REG_OFFSET_NAME(r11),
71 REG_OFFSET_NAME(r10),
72 REG_OFFSET_NAME(r9),
73 REG_OFFSET_NAME(r8),
74 #endif
75 REG_OFFSET_NAME(bx),
76 REG_OFFSET_NAME(cx),
77 REG_OFFSET_NAME(dx),
78 REG_OFFSET_NAME(si),
79 REG_OFFSET_NAME(di),
80 REG_OFFSET_NAME(bp),
81 REG_OFFSET_NAME(ax),
82 #ifdef CONFIG_X86_32
83 REG_OFFSET_NAME(ds),
84 REG_OFFSET_NAME(es),
85 REG_OFFSET_NAME(fs),
86 REG_OFFSET_NAME(gs),
87 #endif
88 REG_OFFSET_NAME(orig_ax),
89 REG_OFFSET_NAME(ip),
90 REG_OFFSET_NAME(cs),
91 REG_OFFSET_NAME(flags),
92 REG_OFFSET_NAME(sp),
93 REG_OFFSET_NAME(ss),
94 REG_OFFSET_END,
95 };
96
97 /**
98 * regs_query_register_offset() - query register offset from its name
99 * @name: the name of a register
100 *
101 * regs_query_register_offset() returns the offset of a register in struct
102 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
103 */
104 int regs_query_register_offset(const char *name)
105 {
106 const struct pt_regs_offset *roff;
107 for (roff = regoffset_table; roff->name != NULL; roff++)
108 if (!strcmp(roff->name, name))
109 return roff->offset;
110 return -EINVAL;
111 }
112
113 /**
114 * regs_query_register_name() - query register name from its offset
115 * @offset: the offset of a register in struct pt_regs.
116 *
117 * regs_query_register_name() returns the name of a register from its
118 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
119 */
120 const char *regs_query_register_name(unsigned int offset)
121 {
122 const struct pt_regs_offset *roff;
123 for (roff = regoffset_table; roff->name != NULL; roff++)
124 if (roff->offset == offset)
125 return roff->name;
126 return NULL;
127 }
128
129 static const int arg_offs_table[] = {
130 #ifdef CONFIG_X86_32
131 [0] = offsetof(struct pt_regs, ax),
132 [1] = offsetof(struct pt_regs, dx),
133 [2] = offsetof(struct pt_regs, cx)
134 #else /* CONFIG_X86_64 */
135 [0] = offsetof(struct pt_regs, di),
136 [1] = offsetof(struct pt_regs, si),
137 [2] = offsetof(struct pt_regs, dx),
138 [3] = offsetof(struct pt_regs, cx),
139 [4] = offsetof(struct pt_regs, r8),
140 [5] = offsetof(struct pt_regs, r9)
141 #endif
142 };
143
144 /*
145 * does not yet catch signals sent when the child dies.
146 * in exit.c or in signal.c.
147 */
148
149 /*
150 * Determines which flags the user has access to [1 = access, 0 = no access].
151 */
152 #define FLAG_MASK_32 ((unsigned long) \
153 (X86_EFLAGS_CF | X86_EFLAGS_PF | \
154 X86_EFLAGS_AF | X86_EFLAGS_ZF | \
155 X86_EFLAGS_SF | X86_EFLAGS_TF | \
156 X86_EFLAGS_DF | X86_EFLAGS_OF | \
157 X86_EFLAGS_RF | X86_EFLAGS_AC))
158
159 /*
160 * Determines whether a value may be installed in a segment register.
161 */
162 static inline bool invalid_selector(u16 value)
163 {
164 return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
165 }
166
167 #ifdef CONFIG_X86_32
168
169 #define FLAG_MASK FLAG_MASK_32
170
171 /*
172 * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
173 * when it traps. The previous stack will be directly underneath the saved
174 * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
175 *
176 * Now, if the stack is empty, '&regs->sp' is out of range. In this
177 * case we try to take the previous stack. To always return a non-null
178 * stack pointer we fall back to regs as stack if no previous stack
179 * exists.
180 *
181 * This is valid only for kernel mode traps.
182 */
183 unsigned long kernel_stack_pointer(struct pt_regs *regs)
184 {
185 unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
186 unsigned long sp = (unsigned long)&regs->sp;
187 struct thread_info *tinfo;
188
189 if (context == (sp & ~(THREAD_SIZE - 1)))
190 return sp;
191
192 tinfo = (struct thread_info *)context;
193 if (tinfo->previous_esp)
194 return tinfo->previous_esp;
195
196 return (unsigned long)regs;
197 }
198 EXPORT_SYMBOL_GPL(kernel_stack_pointer);
199
200 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
201 {
202 BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
203 return &regs->bx + (regno >> 2);
204 }
205
206 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
207 {
208 /*
209 * Returning the value truncates it to 16 bits.
210 */
211 unsigned int retval;
212 if (offset != offsetof(struct user_regs_struct, gs))
213 retval = *pt_regs_access(task_pt_regs(task), offset);
214 else {
215 if (task == current)
216 retval = get_user_gs(task_pt_regs(task));
217 else
218 retval = task_user_gs(task);
219 }
220 return retval;
221 }
222
223 static int set_segment_reg(struct task_struct *task,
224 unsigned long offset, u16 value)
225 {
226 /*
227 * The value argument was already truncated to 16 bits.
228 */
229 if (invalid_selector(value))
230 return -EIO;
231
232 /*
233 * For %cs and %ss we cannot permit a null selector.
234 * We can permit a bogus selector as long as it has USER_RPL.
235 * Null selectors are fine for other segment registers, but
236 * we will never get back to user mode with invalid %cs or %ss
237 * and will take the trap in iret instead. Much code relies
238 * on user_mode() to distinguish a user trap frame (which can
239 * safely use invalid selectors) from a kernel trap frame.
240 */
241 switch (offset) {
242 case offsetof(struct user_regs_struct, cs):
243 case offsetof(struct user_regs_struct, ss):
244 if (unlikely(value == 0))
245 return -EIO;
246
247 default:
248 *pt_regs_access(task_pt_regs(task), offset) = value;
249 break;
250
251 case offsetof(struct user_regs_struct, gs):
252 if (task == current)
253 set_user_gs(task_pt_regs(task), value);
254 else
255 task_user_gs(task) = value;
256 }
257
258 return 0;
259 }
260
261 #else /* CONFIG_X86_64 */
262
263 #define FLAG_MASK (FLAG_MASK_32 | X86_EFLAGS_NT)
264
265 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
266 {
267 BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
268 return &regs->r15 + (offset / sizeof(regs->r15));
269 }
270
271 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
272 {
273 /*
274 * Returning the value truncates it to 16 bits.
275 */
276 unsigned int seg;
277
278 switch (offset) {
279 case offsetof(struct user_regs_struct, fs):
280 if (task == current) {
281 /* Older gas can't assemble movq %?s,%r?? */
282 asm("movl %%fs,%0" : "=r" (seg));
283 return seg;
284 }
285 return task->thread.fsindex;
286 case offsetof(struct user_regs_struct, gs):
287 if (task == current) {
288 asm("movl %%gs,%0" : "=r" (seg));
289 return seg;
290 }
291 return task->thread.gsindex;
292 case offsetof(struct user_regs_struct, ds):
293 if (task == current) {
294 asm("movl %%ds,%0" : "=r" (seg));
295 return seg;
296 }
297 return task->thread.ds;
298 case offsetof(struct user_regs_struct, es):
299 if (task == current) {
300 asm("movl %%es,%0" : "=r" (seg));
301 return seg;
302 }
303 return task->thread.es;
304
305 case offsetof(struct user_regs_struct, cs):
306 case offsetof(struct user_regs_struct, ss):
307 break;
308 }
309 return *pt_regs_access(task_pt_regs(task), offset);
310 }
311
312 static int set_segment_reg(struct task_struct *task,
313 unsigned long offset, u16 value)
314 {
315 /*
316 * The value argument was already truncated to 16 bits.
317 */
318 if (invalid_selector(value))
319 return -EIO;
320
321 switch (offset) {
322 case offsetof(struct user_regs_struct,fs):
323 /*
324 * If this is setting fs as for normal 64-bit use but
325 * setting fs_base has implicitly changed it, leave it.
326 */
327 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
328 task->thread.fs != 0) ||
329 (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
330 task->thread.fs == 0))
331 break;
332 task->thread.fsindex = value;
333 if (task == current)
334 loadsegment(fs, task->thread.fsindex);
335 break;
336 case offsetof(struct user_regs_struct,gs):
337 /*
338 * If this is setting gs as for normal 64-bit use but
339 * setting gs_base has implicitly changed it, leave it.
340 */
341 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
342 task->thread.gs != 0) ||
343 (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
344 task->thread.gs == 0))
345 break;
346 task->thread.gsindex = value;
347 if (task == current)
348 load_gs_index(task->thread.gsindex);
349 break;
350 case offsetof(struct user_regs_struct,ds):
351 task->thread.ds = value;
352 if (task == current)
353 loadsegment(ds, task->thread.ds);
354 break;
355 case offsetof(struct user_regs_struct,es):
356 task->thread.es = value;
357 if (task == current)
358 loadsegment(es, task->thread.es);
359 break;
360
361 /*
362 * Can't actually change these in 64-bit mode.
363 */
364 case offsetof(struct user_regs_struct,cs):
365 if (unlikely(value == 0))
366 return -EIO;
367 #ifdef CONFIG_IA32_EMULATION
368 if (test_tsk_thread_flag(task, TIF_IA32))
369 task_pt_regs(task)->cs = value;
370 #endif
371 break;
372 case offsetof(struct user_regs_struct,ss):
373 if (unlikely(value == 0))
374 return -EIO;
375 #ifdef CONFIG_IA32_EMULATION
376 if (test_tsk_thread_flag(task, TIF_IA32))
377 task_pt_regs(task)->ss = value;
378 #endif
379 break;
380 }
381
382 return 0;
383 }
384
385 #endif /* CONFIG_X86_32 */
386
387 static unsigned long get_flags(struct task_struct *task)
388 {
389 unsigned long retval = task_pt_regs(task)->flags;
390
391 /*
392 * If the debugger set TF, hide it from the readout.
393 */
394 if (test_tsk_thread_flag(task, TIF_FORCED_TF))
395 retval &= ~X86_EFLAGS_TF;
396
397 return retval;
398 }
399
400 static int set_flags(struct task_struct *task, unsigned long value)
401 {
402 struct pt_regs *regs = task_pt_regs(task);
403
404 /*
405 * If the user value contains TF, mark that
406 * it was not "us" (the debugger) that set it.
407 * If not, make sure it stays set if we had.
408 */
409 if (value & X86_EFLAGS_TF)
410 clear_tsk_thread_flag(task, TIF_FORCED_TF);
411 else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
412 value |= X86_EFLAGS_TF;
413
414 regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
415
416 return 0;
417 }
418
419 static int putreg(struct task_struct *child,
420 unsigned long offset, unsigned long value)
421 {
422 switch (offset) {
423 case offsetof(struct user_regs_struct, cs):
424 case offsetof(struct user_regs_struct, ds):
425 case offsetof(struct user_regs_struct, es):
426 case offsetof(struct user_regs_struct, fs):
427 case offsetof(struct user_regs_struct, gs):
428 case offsetof(struct user_regs_struct, ss):
429 return set_segment_reg(child, offset, value);
430
431 case offsetof(struct user_regs_struct, flags):
432 return set_flags(child, value);
433
434 #ifdef CONFIG_X86_64
435 case offsetof(struct user_regs_struct,fs_base):
436 if (value >= TASK_SIZE_OF(child))
437 return -EIO;
438 /*
439 * When changing the segment base, use do_arch_prctl
440 * to set either thread.fs or thread.fsindex and the
441 * corresponding GDT slot.
442 */
443 if (child->thread.fs != value)
444 return do_arch_prctl(child, ARCH_SET_FS, value);
445 return 0;
446 case offsetof(struct user_regs_struct,gs_base):
447 /*
448 * Exactly the same here as the %fs handling above.
449 */
450 if (value >= TASK_SIZE_OF(child))
451 return -EIO;
452 if (child->thread.gs != value)
453 return do_arch_prctl(child, ARCH_SET_GS, value);
454 return 0;
455 #endif
456 }
457
458 *pt_regs_access(task_pt_regs(child), offset) = value;
459 return 0;
460 }
461
462 static unsigned long getreg(struct task_struct *task, unsigned long offset)
463 {
464 switch (offset) {
465 case offsetof(struct user_regs_struct, cs):
466 case offsetof(struct user_regs_struct, ds):
467 case offsetof(struct user_regs_struct, es):
468 case offsetof(struct user_regs_struct, fs):
469 case offsetof(struct user_regs_struct, gs):
470 case offsetof(struct user_regs_struct, ss):
471 return get_segment_reg(task, offset);
472
473 case offsetof(struct user_regs_struct, flags):
474 return get_flags(task);
475
476 #ifdef CONFIG_X86_64
477 case offsetof(struct user_regs_struct, fs_base): {
478 /*
479 * do_arch_prctl may have used a GDT slot instead of
480 * the MSR. To userland, it appears the same either
481 * way, except the %fs segment selector might not be 0.
482 */
483 unsigned int seg = task->thread.fsindex;
484 if (task->thread.fs != 0)
485 return task->thread.fs;
486 if (task == current)
487 asm("movl %%fs,%0" : "=r" (seg));
488 if (seg != FS_TLS_SEL)
489 return 0;
490 return get_desc_base(&task->thread.tls_array[FS_TLS]);
491 }
492 case offsetof(struct user_regs_struct, gs_base): {
493 /*
494 * Exactly the same here as the %fs handling above.
495 */
496 unsigned int seg = task->thread.gsindex;
497 if (task->thread.gs != 0)
498 return task->thread.gs;
499 if (task == current)
500 asm("movl %%gs,%0" : "=r" (seg));
501 if (seg != GS_TLS_SEL)
502 return 0;
503 return get_desc_base(&task->thread.tls_array[GS_TLS]);
504 }
505 #endif
506 }
507
508 return *pt_regs_access(task_pt_regs(task), offset);
509 }
510
511 static int genregs_get(struct task_struct *target,
512 const struct user_regset *regset,
513 unsigned int pos, unsigned int count,
514 void *kbuf, void __user *ubuf)
515 {
516 if (kbuf) {
517 unsigned long *k = kbuf;
518 while (count >= sizeof(*k)) {
519 *k++ = getreg(target, pos);
520 count -= sizeof(*k);
521 pos += sizeof(*k);
522 }
523 } else {
524 unsigned long __user *u = ubuf;
525 while (count >= sizeof(*u)) {
526 if (__put_user(getreg(target, pos), u++))
527 return -EFAULT;
528 count -= sizeof(*u);
529 pos += sizeof(*u);
530 }
531 }
532
533 return 0;
534 }
535
536 static int genregs_set(struct task_struct *target,
537 const struct user_regset *regset,
538 unsigned int pos, unsigned int count,
539 const void *kbuf, const void __user *ubuf)
540 {
541 int ret = 0;
542 if (kbuf) {
543 const unsigned long *k = kbuf;
544 while (count >= sizeof(*k) && !ret) {
545 ret = putreg(target, pos, *k++);
546 count -= sizeof(*k);
547 pos += sizeof(*k);
548 }
549 } else {
550 const unsigned long __user *u = ubuf;
551 while (count >= sizeof(*u) && !ret) {
552 unsigned long word;
553 ret = __get_user(word, u++);
554 if (ret)
555 break;
556 ret = putreg(target, pos, word);
557 count -= sizeof(*u);
558 pos += sizeof(*u);
559 }
560 }
561 return ret;
562 }
563
564 static void ptrace_triggered(struct perf_event *bp,
565 struct perf_sample_data *data,
566 struct pt_regs *regs)
567 {
568 int i;
569 struct thread_struct *thread = &(current->thread);
570
571 /*
572 * Store in the virtual DR6 register the fact that the breakpoint
573 * was hit so the thread's debugger will see it.
574 */
575 for (i = 0; i < HBP_NUM; i++) {
576 if (thread->ptrace_bps[i] == bp)
577 break;
578 }
579
580 thread->debugreg6 |= (DR_TRAP0 << i);
581 }
582
583 /*
584 * Walk through every ptrace breakpoints for this thread and
585 * build the dr7 value on top of their attributes.
586 *
587 */
588 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
589 {
590 int i;
591 int dr7 = 0;
592 struct arch_hw_breakpoint *info;
593
594 for (i = 0; i < HBP_NUM; i++) {
595 if (bp[i] && !bp[i]->attr.disabled) {
596 info = counter_arch_bp(bp[i]);
597 dr7 |= encode_dr7(i, info->len, info->type);
598 }
599 }
600
601 return dr7;
602 }
603
604 static int
605 ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
606 struct task_struct *tsk, int disabled)
607 {
608 int err;
609 int gen_len, gen_type;
610 struct perf_event_attr attr;
611
612 /*
613 * We should have at least an inactive breakpoint at this
614 * slot. It means the user is writing dr7 without having
615 * written the address register first
616 */
617 if (!bp)
618 return -EINVAL;
619
620 err = arch_bp_generic_fields(len, type, &gen_len, &gen_type);
621 if (err)
622 return err;
623
624 attr = bp->attr;
625 attr.bp_len = gen_len;
626 attr.bp_type = gen_type;
627 attr.disabled = disabled;
628
629 return modify_user_hw_breakpoint(bp, &attr);
630 }
631
632 /*
633 * Handle ptrace writes to debug register 7.
634 */
635 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
636 {
637 struct thread_struct *thread = &(tsk->thread);
638 unsigned long old_dr7;
639 int i, orig_ret = 0, rc = 0;
640 int enabled, second_pass = 0;
641 unsigned len, type;
642 struct perf_event *bp;
643
644 if (ptrace_get_breakpoints(tsk) < 0)
645 return -ESRCH;
646
647 data &= ~DR_CONTROL_RESERVED;
648 old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
649 restore:
650 /*
651 * Loop through all the hardware breakpoints, making the
652 * appropriate changes to each.
653 */
654 for (i = 0; i < HBP_NUM; i++) {
655 enabled = decode_dr7(data, i, &len, &type);
656 bp = thread->ptrace_bps[i];
657
658 if (!enabled) {
659 if (bp) {
660 /*
661 * Don't unregister the breakpoints right-away,
662 * unless all register_user_hw_breakpoint()
663 * requests have succeeded. This prevents
664 * any window of opportunity for debug
665 * register grabbing by other users.
666 */
667 if (!second_pass)
668 continue;
669
670 rc = ptrace_modify_breakpoint(bp, len, type,
671 tsk, 1);
672 if (rc)
673 break;
674 }
675 continue;
676 }
677
678 rc = ptrace_modify_breakpoint(bp, len, type, tsk, 0);
679 if (rc)
680 break;
681 }
682 /*
683 * Make a second pass to free the remaining unused breakpoints
684 * or to restore the original breakpoints if an error occurred.
685 */
686 if (!second_pass) {
687 second_pass = 1;
688 if (rc < 0) {
689 orig_ret = rc;
690 data = old_dr7;
691 }
692 goto restore;
693 }
694
695 ptrace_put_breakpoints(tsk);
696
697 return ((orig_ret < 0) ? orig_ret : rc);
698 }
699
700 /*
701 * Handle PTRACE_PEEKUSR calls for the debug register area.
702 */
703 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
704 {
705 struct thread_struct *thread = &(tsk->thread);
706 unsigned long val = 0;
707
708 if (n < HBP_NUM) {
709 struct perf_event *bp;
710
711 if (ptrace_get_breakpoints(tsk) < 0)
712 return -ESRCH;
713
714 bp = thread->ptrace_bps[n];
715 if (!bp)
716 val = 0;
717 else
718 val = bp->hw.info.address;
719
720 ptrace_put_breakpoints(tsk);
721 } else if (n == 6) {
722 val = thread->debugreg6;
723 } else if (n == 7) {
724 val = thread->ptrace_dr7;
725 }
726 return val;
727 }
728
729 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
730 unsigned long addr)
731 {
732 struct perf_event *bp;
733 struct thread_struct *t = &tsk->thread;
734 struct perf_event_attr attr;
735 int err = 0;
736
737 if (ptrace_get_breakpoints(tsk) < 0)
738 return -ESRCH;
739
740 if (!t->ptrace_bps[nr]) {
741 ptrace_breakpoint_init(&attr);
742 /*
743 * Put stub len and type to register (reserve) an inactive but
744 * correct bp
745 */
746 attr.bp_addr = addr;
747 attr.bp_len = HW_BREAKPOINT_LEN_1;
748 attr.bp_type = HW_BREAKPOINT_W;
749 attr.disabled = 1;
750
751 bp = register_user_hw_breakpoint(&attr, ptrace_triggered,
752 NULL, tsk);
753
754 /*
755 * CHECKME: the previous code returned -EIO if the addr wasn't
756 * a valid task virtual addr. The new one will return -EINVAL in
757 * this case.
758 * -EINVAL may be what we want for in-kernel breakpoints users,
759 * but -EIO looks better for ptrace, since we refuse a register
760 * writing for the user. And anyway this is the previous
761 * behaviour.
762 */
763 if (IS_ERR(bp)) {
764 err = PTR_ERR(bp);
765 goto put;
766 }
767
768 t->ptrace_bps[nr] = bp;
769 } else {
770 bp = t->ptrace_bps[nr];
771
772 attr = bp->attr;
773 attr.bp_addr = addr;
774 err = modify_user_hw_breakpoint(bp, &attr);
775 }
776
777 put:
778 ptrace_put_breakpoints(tsk);
779 return err;
780 }
781
782 /*
783 * Handle PTRACE_POKEUSR calls for the debug register area.
784 */
785 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
786 unsigned long val)
787 {
788 struct thread_struct *thread = &(tsk->thread);
789 int rc = 0;
790
791 /* There are no DR4 or DR5 registers */
792 if (n == 4 || n == 5)
793 return -EIO;
794
795 if (n == 6) {
796 thread->debugreg6 = val;
797 goto ret_path;
798 }
799 if (n < HBP_NUM) {
800 rc = ptrace_set_breakpoint_addr(tsk, n, val);
801 if (rc)
802 return rc;
803 }
804 /* All that's left is DR7 */
805 if (n == 7) {
806 rc = ptrace_write_dr7(tsk, val);
807 if (!rc)
808 thread->ptrace_dr7 = val;
809 }
810
811 ret_path:
812 return rc;
813 }
814
815 /*
816 * These access the current or another (stopped) task's io permission
817 * bitmap for debugging or core dump.
818 */
819 static int ioperm_active(struct task_struct *target,
820 const struct user_regset *regset)
821 {
822 return target->thread.io_bitmap_max / regset->size;
823 }
824
825 static int ioperm_get(struct task_struct *target,
826 const struct user_regset *regset,
827 unsigned int pos, unsigned int count,
828 void *kbuf, void __user *ubuf)
829 {
830 if (!target->thread.io_bitmap_ptr)
831 return -ENXIO;
832
833 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
834 target->thread.io_bitmap_ptr,
835 0, IO_BITMAP_BYTES);
836 }
837
838 /*
839 * Called by kernel/ptrace.c when detaching..
840 *
841 * Make sure the single step bit is not set.
842 */
843 void ptrace_disable(struct task_struct *child)
844 {
845 user_disable_single_step(child);
846 #ifdef TIF_SYSCALL_EMU
847 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
848 #endif
849 }
850
851 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
852 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
853 #endif
854
855 long arch_ptrace(struct task_struct *child, long request,
856 unsigned long addr, unsigned long data)
857 {
858 int ret;
859 unsigned long __user *datap = (unsigned long __user *)data;
860
861 switch (request) {
862 /* read the word at location addr in the USER area. */
863 case PTRACE_PEEKUSR: {
864 unsigned long tmp;
865
866 ret = -EIO;
867 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
868 break;
869
870 tmp = 0; /* Default return condition */
871 if (addr < sizeof(struct user_regs_struct))
872 tmp = getreg(child, addr);
873 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
874 addr <= offsetof(struct user, u_debugreg[7])) {
875 addr -= offsetof(struct user, u_debugreg[0]);
876 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
877 }
878 ret = put_user(tmp, datap);
879 break;
880 }
881
882 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
883 ret = -EIO;
884 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
885 break;
886
887 if (addr < sizeof(struct user_regs_struct))
888 ret = putreg(child, addr, data);
889 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
890 addr <= offsetof(struct user, u_debugreg[7])) {
891 addr -= offsetof(struct user, u_debugreg[0]);
892 ret = ptrace_set_debugreg(child,
893 addr / sizeof(data), data);
894 }
895 break;
896
897 case PTRACE_GETREGS: /* Get all gp regs from the child. */
898 return copy_regset_to_user(child,
899 task_user_regset_view(current),
900 REGSET_GENERAL,
901 0, sizeof(struct user_regs_struct),
902 datap);
903
904 case PTRACE_SETREGS: /* Set all gp regs in the child. */
905 return copy_regset_from_user(child,
906 task_user_regset_view(current),
907 REGSET_GENERAL,
908 0, sizeof(struct user_regs_struct),
909 datap);
910
911 case PTRACE_GETFPREGS: /* Get the child FPU state. */
912 return copy_regset_to_user(child,
913 task_user_regset_view(current),
914 REGSET_FP,
915 0, sizeof(struct user_i387_struct),
916 datap);
917
918 case PTRACE_SETFPREGS: /* Set the child FPU state. */
919 return copy_regset_from_user(child,
920 task_user_regset_view(current),
921 REGSET_FP,
922 0, sizeof(struct user_i387_struct),
923 datap);
924
925 #ifdef CONFIG_X86_32
926 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
927 return copy_regset_to_user(child, &user_x86_32_view,
928 REGSET_XFP,
929 0, sizeof(struct user_fxsr_struct),
930 datap) ? -EIO : 0;
931
932 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
933 return copy_regset_from_user(child, &user_x86_32_view,
934 REGSET_XFP,
935 0, sizeof(struct user_fxsr_struct),
936 datap) ? -EIO : 0;
937 #endif
938
939 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
940 case PTRACE_GET_THREAD_AREA:
941 if ((int) addr < 0)
942 return -EIO;
943 ret = do_get_thread_area(child, addr,
944 (struct user_desc __user *)data);
945 break;
946
947 case PTRACE_SET_THREAD_AREA:
948 if ((int) addr < 0)
949 return -EIO;
950 ret = do_set_thread_area(child, addr,
951 (struct user_desc __user *)data, 0);
952 break;
953 #endif
954
955 #ifdef CONFIG_X86_64
956 /* normal 64bit interface to access TLS data.
957 Works just like arch_prctl, except that the arguments
958 are reversed. */
959 case PTRACE_ARCH_PRCTL:
960 ret = do_arch_prctl(child, data, addr);
961 break;
962 #endif
963
964 default:
965 ret = ptrace_request(child, request, addr, data);
966 break;
967 }
968
969 return ret;
970 }
971
972 #ifdef CONFIG_IA32_EMULATION
973
974 #include <linux/compat.h>
975 #include <linux/syscalls.h>
976 #include <asm/ia32.h>
977 #include <asm/user32.h>
978
979 #define R32(l,q) \
980 case offsetof(struct user32, regs.l): \
981 regs->q = value; break
982
983 #define SEG32(rs) \
984 case offsetof(struct user32, regs.rs): \
985 return set_segment_reg(child, \
986 offsetof(struct user_regs_struct, rs), \
987 value); \
988 break
989
990 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
991 {
992 struct pt_regs *regs = task_pt_regs(child);
993
994 switch (regno) {
995
996 SEG32(cs);
997 SEG32(ds);
998 SEG32(es);
999 SEG32(fs);
1000 SEG32(gs);
1001 SEG32(ss);
1002
1003 R32(ebx, bx);
1004 R32(ecx, cx);
1005 R32(edx, dx);
1006 R32(edi, di);
1007 R32(esi, si);
1008 R32(ebp, bp);
1009 R32(eax, ax);
1010 R32(eip, ip);
1011 R32(esp, sp);
1012
1013 case offsetof(struct user32, regs.orig_eax):
1014 /*
1015 * A 32-bit debugger setting orig_eax means to restore
1016 * the state of the task restarting a 32-bit syscall.
1017 * Make sure we interpret the -ERESTART* codes correctly
1018 * in case the task is not actually still sitting at the
1019 * exit from a 32-bit syscall with TS_COMPAT still set.
1020 */
1021 regs->orig_ax = value;
1022 if (syscall_get_nr(child, regs) >= 0)
1023 task_thread_info(child)->status |= TS_COMPAT;
1024 break;
1025
1026 case offsetof(struct user32, regs.eflags):
1027 return set_flags(child, value);
1028
1029 case offsetof(struct user32, u_debugreg[0]) ...
1030 offsetof(struct user32, u_debugreg[7]):
1031 regno -= offsetof(struct user32, u_debugreg[0]);
1032 return ptrace_set_debugreg(child, regno / 4, value);
1033
1034 default:
1035 if (regno > sizeof(struct user32) || (regno & 3))
1036 return -EIO;
1037
1038 /*
1039 * Other dummy fields in the virtual user structure
1040 * are ignored
1041 */
1042 break;
1043 }
1044 return 0;
1045 }
1046
1047 #undef R32
1048 #undef SEG32
1049
1050 #define R32(l,q) \
1051 case offsetof(struct user32, regs.l): \
1052 *val = regs->q; break
1053
1054 #define SEG32(rs) \
1055 case offsetof(struct user32, regs.rs): \
1056 *val = get_segment_reg(child, \
1057 offsetof(struct user_regs_struct, rs)); \
1058 break
1059
1060 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1061 {
1062 struct pt_regs *regs = task_pt_regs(child);
1063
1064 switch (regno) {
1065
1066 SEG32(ds);
1067 SEG32(es);
1068 SEG32(fs);
1069 SEG32(gs);
1070
1071 R32(cs, cs);
1072 R32(ss, ss);
1073 R32(ebx, bx);
1074 R32(ecx, cx);
1075 R32(edx, dx);
1076 R32(edi, di);
1077 R32(esi, si);
1078 R32(ebp, bp);
1079 R32(eax, ax);
1080 R32(orig_eax, orig_ax);
1081 R32(eip, ip);
1082 R32(esp, sp);
1083
1084 case offsetof(struct user32, regs.eflags):
1085 *val = get_flags(child);
1086 break;
1087
1088 case offsetof(struct user32, u_debugreg[0]) ...
1089 offsetof(struct user32, u_debugreg[7]):
1090 regno -= offsetof(struct user32, u_debugreg[0]);
1091 *val = ptrace_get_debugreg(child, regno / 4);
1092 break;
1093
1094 default:
1095 if (regno > sizeof(struct user32) || (regno & 3))
1096 return -EIO;
1097
1098 /*
1099 * Other dummy fields in the virtual user structure
1100 * are ignored
1101 */
1102 *val = 0;
1103 break;
1104 }
1105 return 0;
1106 }
1107
1108 #undef R32
1109 #undef SEG32
1110
1111 static int genregs32_get(struct task_struct *target,
1112 const struct user_regset *regset,
1113 unsigned int pos, unsigned int count,
1114 void *kbuf, void __user *ubuf)
1115 {
1116 if (kbuf) {
1117 compat_ulong_t *k = kbuf;
1118 while (count >= sizeof(*k)) {
1119 getreg32(target, pos, k++);
1120 count -= sizeof(*k);
1121 pos += sizeof(*k);
1122 }
1123 } else {
1124 compat_ulong_t __user *u = ubuf;
1125 while (count >= sizeof(*u)) {
1126 compat_ulong_t word;
1127 getreg32(target, pos, &word);
1128 if (__put_user(word, u++))
1129 return -EFAULT;
1130 count -= sizeof(*u);
1131 pos += sizeof(*u);
1132 }
1133 }
1134
1135 return 0;
1136 }
1137
1138 static int genregs32_set(struct task_struct *target,
1139 const struct user_regset *regset,
1140 unsigned int pos, unsigned int count,
1141 const void *kbuf, const void __user *ubuf)
1142 {
1143 int ret = 0;
1144 if (kbuf) {
1145 const compat_ulong_t *k = kbuf;
1146 while (count >= sizeof(*k) && !ret) {
1147 ret = putreg32(target, pos, *k++);
1148 count -= sizeof(*k);
1149 pos += sizeof(*k);
1150 }
1151 } else {
1152 const compat_ulong_t __user *u = ubuf;
1153 while (count >= sizeof(*u) && !ret) {
1154 compat_ulong_t word;
1155 ret = __get_user(word, u++);
1156 if (ret)
1157 break;
1158 ret = putreg32(target, pos, word);
1159 count -= sizeof(*u);
1160 pos += sizeof(*u);
1161 }
1162 }
1163 return ret;
1164 }
1165
1166 #ifdef CONFIG_X86_X32_ABI
1167 static long x32_arch_ptrace(struct task_struct *child,
1168 compat_long_t request, compat_ulong_t caddr,
1169 compat_ulong_t cdata)
1170 {
1171 unsigned long addr = caddr;
1172 unsigned long data = cdata;
1173 void __user *datap = compat_ptr(data);
1174 int ret;
1175
1176 switch (request) {
1177 /* Read 32bits at location addr in the USER area. Only allow
1178 to return the lower 32bits of segment and debug registers. */
1179 case PTRACE_PEEKUSR: {
1180 u32 tmp;
1181
1182 ret = -EIO;
1183 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1184 addr < offsetof(struct user_regs_struct, cs))
1185 break;
1186
1187 tmp = 0; /* Default return condition */
1188 if (addr < sizeof(struct user_regs_struct))
1189 tmp = getreg(child, addr);
1190 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1191 addr <= offsetof(struct user, u_debugreg[7])) {
1192 addr -= offsetof(struct user, u_debugreg[0]);
1193 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1194 }
1195 ret = put_user(tmp, (__u32 __user *)datap);
1196 break;
1197 }
1198
1199 /* Write the word at location addr in the USER area. Only allow
1200 to update segment and debug registers with the upper 32bits
1201 zero-extended. */
1202 case PTRACE_POKEUSR:
1203 ret = -EIO;
1204 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1205 addr < offsetof(struct user_regs_struct, cs))
1206 break;
1207
1208 if (addr < sizeof(struct user_regs_struct))
1209 ret = putreg(child, addr, data);
1210 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1211 addr <= offsetof(struct user, u_debugreg[7])) {
1212 addr -= offsetof(struct user, u_debugreg[0]);
1213 ret = ptrace_set_debugreg(child,
1214 addr / sizeof(data), data);
1215 }
1216 break;
1217
1218 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1219 return copy_regset_to_user(child,
1220 task_user_regset_view(current),
1221 REGSET_GENERAL,
1222 0, sizeof(struct user_regs_struct),
1223 datap);
1224
1225 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1226 return copy_regset_from_user(child,
1227 task_user_regset_view(current),
1228 REGSET_GENERAL,
1229 0, sizeof(struct user_regs_struct),
1230 datap);
1231
1232 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1233 return copy_regset_to_user(child,
1234 task_user_regset_view(current),
1235 REGSET_FP,
1236 0, sizeof(struct user_i387_struct),
1237 datap);
1238
1239 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1240 return copy_regset_from_user(child,
1241 task_user_regset_view(current),
1242 REGSET_FP,
1243 0, sizeof(struct user_i387_struct),
1244 datap);
1245
1246 default:
1247 return compat_ptrace_request(child, request, addr, data);
1248 }
1249
1250 return ret;
1251 }
1252 #endif
1253
1254 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1255 compat_ulong_t caddr, compat_ulong_t cdata)
1256 {
1257 unsigned long addr = caddr;
1258 unsigned long data = cdata;
1259 void __user *datap = compat_ptr(data);
1260 int ret;
1261 __u32 val;
1262
1263 #ifdef CONFIG_X86_X32_ABI
1264 if (!is_ia32_task())
1265 return x32_arch_ptrace(child, request, caddr, cdata);
1266 #endif
1267
1268 switch (request) {
1269 case PTRACE_PEEKUSR:
1270 ret = getreg32(child, addr, &val);
1271 if (ret == 0)
1272 ret = put_user(val, (__u32 __user *)datap);
1273 break;
1274
1275 case PTRACE_POKEUSR:
1276 ret = putreg32(child, addr, data);
1277 break;
1278
1279 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1280 return copy_regset_to_user(child, &user_x86_32_view,
1281 REGSET_GENERAL,
1282 0, sizeof(struct user_regs_struct32),
1283 datap);
1284
1285 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1286 return copy_regset_from_user(child, &user_x86_32_view,
1287 REGSET_GENERAL, 0,
1288 sizeof(struct user_regs_struct32),
1289 datap);
1290
1291 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1292 return copy_regset_to_user(child, &user_x86_32_view,
1293 REGSET_FP, 0,
1294 sizeof(struct user_i387_ia32_struct),
1295 datap);
1296
1297 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1298 return copy_regset_from_user(
1299 child, &user_x86_32_view, REGSET_FP,
1300 0, sizeof(struct user_i387_ia32_struct), datap);
1301
1302 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1303 return copy_regset_to_user(child, &user_x86_32_view,
1304 REGSET_XFP, 0,
1305 sizeof(struct user32_fxsr_struct),
1306 datap);
1307
1308 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1309 return copy_regset_from_user(child, &user_x86_32_view,
1310 REGSET_XFP, 0,
1311 sizeof(struct user32_fxsr_struct),
1312 datap);
1313
1314 case PTRACE_GET_THREAD_AREA:
1315 case PTRACE_SET_THREAD_AREA:
1316 return arch_ptrace(child, request, addr, data);
1317
1318 default:
1319 return compat_ptrace_request(child, request, addr, data);
1320 }
1321
1322 return ret;
1323 }
1324
1325 #endif /* CONFIG_IA32_EMULATION */
1326
1327 #ifdef CONFIG_X86_64
1328
1329 static struct user_regset x86_64_regsets[] __read_mostly = {
1330 [REGSET_GENERAL] = {
1331 .core_note_type = NT_PRSTATUS,
1332 .n = sizeof(struct user_regs_struct) / sizeof(long),
1333 .size = sizeof(long), .align = sizeof(long),
1334 .get = genregs_get, .set = genregs_set
1335 },
1336 [REGSET_FP] = {
1337 .core_note_type = NT_PRFPREG,
1338 .n = sizeof(struct user_i387_struct) / sizeof(long),
1339 .size = sizeof(long), .align = sizeof(long),
1340 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1341 },
1342 [REGSET_XSTATE] = {
1343 .core_note_type = NT_X86_XSTATE,
1344 .size = sizeof(u64), .align = sizeof(u64),
1345 .active = xstateregs_active, .get = xstateregs_get,
1346 .set = xstateregs_set
1347 },
1348 [REGSET_IOPERM64] = {
1349 .core_note_type = NT_386_IOPERM,
1350 .n = IO_BITMAP_LONGS,
1351 .size = sizeof(long), .align = sizeof(long),
1352 .active = ioperm_active, .get = ioperm_get
1353 },
1354 };
1355
1356 static const struct user_regset_view user_x86_64_view = {
1357 .name = "x86_64", .e_machine = EM_X86_64,
1358 .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1359 };
1360
1361 #else /* CONFIG_X86_32 */
1362
1363 #define user_regs_struct32 user_regs_struct
1364 #define genregs32_get genregs_get
1365 #define genregs32_set genregs_set
1366
1367 #endif /* CONFIG_X86_64 */
1368
1369 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1370 static struct user_regset x86_32_regsets[] __read_mostly = {
1371 [REGSET_GENERAL] = {
1372 .core_note_type = NT_PRSTATUS,
1373 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1374 .size = sizeof(u32), .align = sizeof(u32),
1375 .get = genregs32_get, .set = genregs32_set
1376 },
1377 [REGSET_FP] = {
1378 .core_note_type = NT_PRFPREG,
1379 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1380 .size = sizeof(u32), .align = sizeof(u32),
1381 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1382 },
1383 [REGSET_XFP] = {
1384 .core_note_type = NT_PRXFPREG,
1385 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1386 .size = sizeof(u32), .align = sizeof(u32),
1387 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1388 },
1389 [REGSET_XSTATE] = {
1390 .core_note_type = NT_X86_XSTATE,
1391 .size = sizeof(u64), .align = sizeof(u64),
1392 .active = xstateregs_active, .get = xstateregs_get,
1393 .set = xstateregs_set
1394 },
1395 [REGSET_TLS] = {
1396 .core_note_type = NT_386_TLS,
1397 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1398 .size = sizeof(struct user_desc),
1399 .align = sizeof(struct user_desc),
1400 .active = regset_tls_active,
1401 .get = regset_tls_get, .set = regset_tls_set
1402 },
1403 [REGSET_IOPERM32] = {
1404 .core_note_type = NT_386_IOPERM,
1405 .n = IO_BITMAP_BYTES / sizeof(u32),
1406 .size = sizeof(u32), .align = sizeof(u32),
1407 .active = ioperm_active, .get = ioperm_get
1408 },
1409 };
1410
1411 static const struct user_regset_view user_x86_32_view = {
1412 .name = "i386", .e_machine = EM_386,
1413 .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1414 };
1415 #endif
1416
1417 /*
1418 * This represents bytes 464..511 in the memory layout exported through
1419 * the REGSET_XSTATE interface.
1420 */
1421 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1422
1423 void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1424 {
1425 #ifdef CONFIG_X86_64
1426 x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1427 #endif
1428 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1429 x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1430 #endif
1431 xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1432 }
1433
1434 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1435 {
1436 #ifdef CONFIG_IA32_EMULATION
1437 if (test_tsk_thread_flag(task, TIF_IA32))
1438 #endif
1439 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1440 return &user_x86_32_view;
1441 #endif
1442 #ifdef CONFIG_X86_64
1443 return &user_x86_64_view;
1444 #endif
1445 }
1446
1447 static void fill_sigtrap_info(struct task_struct *tsk,
1448 struct pt_regs *regs,
1449 int error_code, int si_code,
1450 struct siginfo *info)
1451 {
1452 tsk->thread.trap_nr = X86_TRAP_DB;
1453 tsk->thread.error_code = error_code;
1454
1455 memset(info, 0, sizeof(*info));
1456 info->si_signo = SIGTRAP;
1457 info->si_code = si_code;
1458 info->si_addr = user_mode_vm(regs) ? (void __user *)regs->ip : NULL;
1459 }
1460
1461 void user_single_step_siginfo(struct task_struct *tsk,
1462 struct pt_regs *regs,
1463 struct siginfo *info)
1464 {
1465 fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1466 }
1467
1468 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1469 int error_code, int si_code)
1470 {
1471 struct siginfo info;
1472
1473 fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1474 /* Send us the fake SIGTRAP */
1475 force_sig_info(SIGTRAP, &info, tsk);
1476 }
1477
1478
1479 #ifdef CONFIG_X86_32
1480 # define IS_IA32 1
1481 #elif defined CONFIG_IA32_EMULATION
1482 # define IS_IA32 is_compat_task()
1483 #else
1484 # define IS_IA32 0
1485 #endif
1486
1487 /*
1488 * We must return the syscall number to actually look up in the table.
1489 * This can be -1L to skip running any syscall at all.
1490 */
1491 long syscall_trace_enter(struct pt_regs *regs)
1492 {
1493 long ret = 0;
1494
1495 user_exit();
1496
1497 /*
1498 * If we stepped into a sysenter/syscall insn, it trapped in
1499 * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1500 * If user-mode had set TF itself, then it's still clear from
1501 * do_debug() and we need to set it again to restore the user
1502 * state. If we entered on the slow path, TF was already set.
1503 */
1504 if (test_thread_flag(TIF_SINGLESTEP))
1505 regs->flags |= X86_EFLAGS_TF;
1506
1507 /* do the secure computing check first */
1508 if (secure_computing(regs->orig_ax)) {
1509 /* seccomp failures shouldn't expose any additional code. */
1510 ret = -1L;
1511 goto out;
1512 }
1513
1514 if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1515 ret = -1L;
1516
1517 if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1518 tracehook_report_syscall_entry(regs))
1519 ret = -1L;
1520
1521 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1522 trace_sys_enter(regs, regs->orig_ax);
1523
1524 if (IS_IA32)
1525 audit_syscall_entry(AUDIT_ARCH_I386,
1526 regs->orig_ax,
1527 regs->bx, regs->cx,
1528 regs->dx, regs->si);
1529 #ifdef CONFIG_X86_64
1530 else
1531 audit_syscall_entry(AUDIT_ARCH_X86_64,
1532 regs->orig_ax,
1533 regs->di, regs->si,
1534 regs->dx, regs->r10);
1535 #endif
1536
1537 out:
1538 return ret ?: regs->orig_ax;
1539 }
1540
1541 void syscall_trace_leave(struct pt_regs *regs)
1542 {
1543 bool step;
1544
1545 /*
1546 * We may come here right after calling schedule_user()
1547 * or do_notify_resume(), in which case we can be in RCU
1548 * user mode.
1549 */
1550 user_exit();
1551
1552 audit_syscall_exit(regs);
1553
1554 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1555 trace_sys_exit(regs, regs->ax);
1556
1557 /*
1558 * If TIF_SYSCALL_EMU is set, we only get here because of
1559 * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1560 * We already reported this syscall instruction in
1561 * syscall_trace_enter().
1562 */
1563 step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
1564 !test_thread_flag(TIF_SYSCALL_EMU);
1565 if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1566 tracehook_report_syscall_exit(regs, step);
1567
1568 user_enter();
1569 }
CRIS linux kernel tree